Removing older entries from datastore

I am using java to query google cloud datastore in order to find out whether an entry has been there more than one day, and if yes then delete the entry. I have something like this:

    if (requestUploaded == true) {

     datastore.delete(row_to_delete);

I want to add a logic where:

a) I get the current time.

b) Then check if datastore entry is older than one day, if so, then delete.

Thanks!

Based on your explanation of the issue, I am not aware of any built-in method for creation time in Cloud Datastore entities, so my explanation assumes that you have a created property in your entity.

Getting current time

You can construct a new Date object without any arguments to get the current date and time:

import java.util.Date;

Date d = new Date();

Optionally, you can use Timestamp.now() when creating your Entity, as per the documentation:

Entity task = Entity.newBuilder(taskKey)
    .set("category", "Personal")
    .set("created", Timestamp.now())
    .set("description",
      StringValue.newBuilder("Learn Cloud Datastore").setExcludeFromIndexes(true).build())
    .build();

Comparing the entity's creation time to the current date and time

You can leverage the following sample code to fetch all entities where created property, which is the date and time that the entity was created, is less than the current time, which is defined by Timestamp.now()

Query<Entity> query = Query.newEntityQueryBuilder()
    .setKind("Person")
    .setFilter(PropertyFilter.lt("created", Timestamp.now()))
    .build();
QueryResults<Entity> results = datastore.run(query);
while (results.hasNext()) {
  Entity currentEntity = results.next();
  System.out.println(currentEntity.getString("name"));
}

You can refer to the PropertyFilter operator documentation for more details on filtering.

Deleting an entity

Lastly, you can delete an entity by its given key:

datastore.delete(taskKey);